Yep, that’s what I found too - sometimes the fb button takes a touch longer to load than the rest of the page and it seems to throw everything else on the page out. My initial thought was the block the fb icon goes into gets a bit of extra height as it’s rendering and then shrinks slightly again, and the jump around in height seemed to block out the links on the page. But then I never checked it out properly, i get enough of this sort of thing at work. I’ve seen it on Win7/Chrome and Win8/Chrome.
On a related note, if you’re looking at stuff like this - I’ve also noticed sometimes on Android/Chrome, the lag in loading the fb icon on the thread listing shifts everything down a second or so after the rest of the page has loaded - usually just as I click a link, resulting in me getting whatever thread is a couple lines above.